Control method for driving a ripper

Abstract

A method for driving a ripper is provided in which the movement of a ripper attached to the rear of the body of a bulldozer is controlled. The method includes a first step in which the ripper is operated while the bulldozer is moving forward or is stopped, a second step in which the bulldozer is reversed and the ripper is raised, and a third step in which the ripper is automatically raised.

The invention claimed is: 
     
       1. A control method for automatically controlling a ripper attached to a rear portion of a body of a bulldozer, the bulldozer having a ripper lifting device configured to raise and lower the ripper, a ripper tilting device configured to tilt the ripper in and out, an operating lever that is moveably provided and configured to actuate the ripper lifting device and the ripper tilting device, and a steering lever that is moveably provided and configured to control a drive unit of the bulldozer, said method comprising:
 a first step in which it is determined whether ripping work by the ripper has ended; 
 a second step in which at least a first control of pulling the ripper out of a ground is automatically executed when it is determined that the ripping work has ended. 
 
     
     
       2. The control method for automatically controlling a ripper according to  claim 1 , further comprising
 a third step in which a user selects among a plurality of automatic control modes, the automatic control modes including at least a first mode in which only the first control is executed automatically in the second step. 
 
     
     
       3. The control method for automatically controlling a ripper according to  claim 2 , wherein
 it is determined that the ripping work has been ended when the steering lever has been moved to a reverse side during the ripping work and the operating lever has been moved to a lift position. 
 
     
     
       4. The control method for automatically controlling a ripper according to  claim 3 , wherein
 the automatic control modes include a second mode in which a second control of tilting back the ripper is executed automatically in the second step when it is determined both that the ripping work has ended and that the operating lever has been moved to a tilt-back position. 
 
     
     
       5. The control method for automatically controlling a ripper according to  claim 3 , further comprising
 a fourth step in which the first control is released when it is determined that the hydraulic pressure in a hydraulic circuit of the bulldozer has risen over a specific relief pressure, or that the bulldozer is moving forward or is stopped, or that the operating lever has been moved to a lowering position, or that at least a specific amount of time has elapsed since the operating lever was moved to the lift position. 
 
     
     
       6. The control method for automatically controlling a ripper according to  claim 4 , further comprising
 a fourth step in which the second control is released when it is determined that the hydraulic pressure in a hydraulic circuit of the bulldozer has risen over a specific relief pressure, or that the bulldozer is moving forward or is stopped, or that the operating lever has been moved to a tilt-in position, or that at least a specific amount of time has elapsed since the operating lever was moved to the tilt-back position. 
 
     
     
       7. The control method for automatically controlling a ripper according to  claim 4 , wherein
 the automatic control modes include a third mode in which the first and second controls are executed automatically when it is detected that the ripping work has ended. 
 
     
     
       8. The control method for automatically controlling a ripper according to  claim 1 , wherein
 it is determined that the ripping work has been ended when the steering lever has been moved to a reverse side during the ripping work and the operating lever has been moved to a lift position. 
 
     
     
       9. The control method for automatically controlling a ripper according to  claim 4 , further comprising;
 a fourth step in which the first control is released when it is determined that the hydraulic pressure in a hydraulic circuit of the bulldozer has risen over a specific relief pressure, or that the bulldozer is moving forward or is stopped, or that the operating lever has been moved to a lowering position, or that at least a specific amount of time has elapsed since operating lever was moved to the lift position; and 
 a fifth step in which the second control is released when it is determined that the hydraulic pressure in a hydraulic circuit of the bulldozer has risen over a specific relief pressure, or that the bulldozer is moving forward or is stopped, or that the operating lever has been moved to a tilt-in position, or that at least a specific amount of time has elapsed since the operating lever was moved to the tilt-back position.